When using nuclear energy and radiation, it is frequently required to measure gamma ray and neutron discriminately. For example, gamma ray and neutron generated from nuclear spent fuel are measured to determine the amount of the nuclear materials included in the spent fuel.
A detecting device for measuring gamma ray or neutron could be inserted in a guide tube of nuclear fuel assembly to measure the radiation. However, with a general conventional detecting device, a detecting device for gamma ray and a detecting device for neutron have to be inserted respectively to measure the gamma ray and neutron since the radius of the guide tube is limited.
In other words, with the general conventional radiation detecting device, gamma ray and neutron cannot be detected at once.